This invention relates to a novel compound for increasing the storage life of food and feed products which normally spoil or lose flavor. Additionally, this invention relates to a method for increasing the storage life of such food and feed products and to food and feed product compositions containing such compounds. In particular, this invention is related to inhibiting the growth of pathogens and food spoilage organisms in food and feed products which normally spoil or lose flavor during storage.
Deterioration due to pathogenic and spoilage organisms occurs extensively in untreated foodstuffs such as bakery products, fish, meats, fruits, vegetables and dairy products. Industrial food processing plants incur losses both in the form of returned, deteriorated products and of impaired sales owing to inferior keeping quality of the products. Consumers, also, are caused direct losses by such deterioration but, in addition, they also run health risks because of the toxins formed by pathogens which may already be produced before the growth of such pathogens is observable. Heretofore, attempts have been made to prevent or inhibit the growth of microorganisms such as pathogens and food spoilage organisms by using packaging materials which have been treated by a variety of substances and by intensifying plant hygiene and thus reducing the amount of pathogenic and food spoilage organism infection. Intensified food plant hygiene has successfully lowered the frequency of pathogenic and food spoilage organisms to a significant degree, however it is impossible, in practice, to solve the problem completely by this approach, since it has not been possible to reduce to a sufficiently low level the organism infection by which food is contaminated even by such expedients as filtration of intake air and ultraviolet light treatment.
Aerobic microorganisms are deposited on the surface of food or feed through post-processing contamination from the air, from the hands of an operator, from equipment and utensils and other means. Typical examples are the formation of slime on the surfaces of slaughtered animal carcasses, or the growth of bacterial colonies on sliced sausages.
Since post-processing microbial contamination, in most cases, remains on the surface of the food or feed, aerobic microorganisms generally can multiply only on the superficial layers of the food or feed. Accordingly, the measures aimed at fighting such microorganisms are concentrated on the superficial layer and the desired preventative effect can thereby be achieved. The procedures applied heretofore for the purpose of applying chemical or equivalent inhibitors of microorganism growth on the superficial layer of food or feed products have been dipping the food in a solution of chemical preservative, spraying a chemical preservative solution onto the surface of food or feed and impregnating packaging material with a chemical preservative. A wide variety of such chemical preservatives have heretofore been used.
For instance, U.S. Pat. No. 2,711,976 suggests the use of amino acids to increase the resistance of custard foods to spoilage organisms and Staphylococcus aureus. U.S. Pat. No. 2,898,372 suggests calcium acetate propionate as a bread treating composition. U.S. Pat. No. 2,866,819 suggests the use of sorbic acid as a preservative in foods. U.S. Pat. No. 2,910,368 discloses the use of EDTA with sorbic acid to increase the shelf life of vegetables. U.S. Pat. No. 2,992,114 suggests the use of sorbic acid and a mild heat treatment for the preservation of fruits and vegetables. In a paper published in Applied Microbiology, Volume 18, pages 68-75 (July, 1969), Preonas et al reported on the use of a mixture of sorbic acid and propionic acid to retard the growth of S. aureus on the surfaces of custard pies.
In copending application Ser. No. 222,200 filed Jan. 2, 1981 now U.S. Pat. No. 4,356,317 and assigned to the present assignee, there are described acyloxyalkenoic acids which are characterized as hexenoic acids having up to one alkyl substituent on the alpha carbon atom and an acyloxy substituent on a carbon atom, the acyloxy substituent being represented by RCOO--, where R is alkyl, and their salts. In particular, there are described such compounds in which acyloxy is acetoxy, and, more particularly, a mixture of isomeric acids which are 6-acyloxy-4-hexenoic and 4-acyl-oxy-5-hexenoic acids and their salts.
In accordance with the present invention, there is described and claimed a method of inhibiting the growth of pathogens and spoilage organisms in foods and feeds by treating same with acyloxyhexenoic acids and there are described and claimed food and feed compositions containing such acids.